Rebound phenomenon and its risk factors after hemiepiphysiodesis using tension band plate in children with coronal angular deformity.

BACKGROUND: This study was performed to evaluate the rebound phenomenon after the correction of coronal angular deformity by hemiepiphysiodesis using tension band plate in children and to identify its risk factors. METHODS: We reviewed 50 children (mean age, 11.0 ± 2.5 years) with 94 physes who had undergone hemiepiphysiodesis using tension band plate due to coronal angular deformity of the lower limb. Patients' demographic data including sex, age at initial surgery and plate removal, affected bone (distal femur or proximal tibia), affected side, and body mass index were collected. The mechanical lateral distal femoral angle (mLDFA) and the mechanical medial proximal tibial angle (mMPTA) were measured from the teleradiogram, Physes were divided into rebound and non-rebound group, and rebound group was defined as the physes which had ≥ 5° of mLDFA or mMPTA returning to its original deformity. Generalized estimating equation based multivariable analysis was used to identify the risk factors for the rebound phenomenon after the deformity correction. RESULTS: A total of 41 physes classified into rebound group and 53 physes into non-rebound group. There were significant differences in the age at initial surgery (p = 0.004), the age at implant removal (p = 0.002), the amount of correction (p = 0.001), and the rate of correction (p < 0.001) between two groups. The rate of correction was significantly associated with the rebound phenomenon (p = 0.044). The risk of rebound phenomenon was 1.2-fold higher as the rate of correction increased by 1° per year. The cutoff values of the correction rate between the two groups were 6.9°/year (p < 0.001). CONCLUSIONS: This study showed that the rebound group had younger age and faster correction rate than those in the non-rebound group. In addition, the correction rate for deformity was a significant risk factor for the rebound phenomenon after hemiepiphysiodesis using the tension band plate. Close monitoring after implant removal is required for children who have a rapid correction rate over 7°/year.

Effect of Screw Configuration on the Rate of Correction for Guided Growth Using the Tension-band Plate.

BACKGROUND: This study investigated the effect of screw configuration on the rate of correction of coronal angular deformity of the knee joint in children who underwent guided growth using the tension-band plate. METHODS: Consecutive patients (76 patients with 154 physes; mean age: 11.8±2.2 y) who underwent guided growth using the tension-band plate for coronal angular deformity (genu varum or genu valgum) were included. The mechanical lateral distal femoral angle, mechanical medial proximal tibial angle, and screw angle were measured from the teleroentgenograms of preoperative and postoperative periodic follow-up visits. RESULTS: The mean initial screw angle and the mean rate of correction were 16.7±10.5 degrees and 6.5±5.3 degrees per year, respectively. The rate of correction was significantly affected by age at surgery, sex, physis treated, severity of deformity, and rate of change in screw angle (all P<0.001). However, the initial screw angle and type of deformity did not affect the rate of correction. The rate of correction per year was 3.6 degrees higher in boys than in girls and 2.8 degrees higher in the distal femur than in the proximal tibia. A 1 degree increase in the rate of change in screw angle was associated with a 0.5 degree increase in the correction rate. Screw angle significantly increased with follow-up duration (P<0.001) and the change in screw angle was significantly affected by age, sex, and physis treated (all P<0.001). CONCLUSIONS: This study demonstrated that screw configuration did not affect the correction rate of coronal angular deformity for guided growth using the tension-band plate. Therefore, surgeons only need to insert the screws according to anatomic restriction, not considering the screw configuration when using the tension-band plate for guided growth in children. LEVEL OF EVIDENCE: Prognostic level III.

Leg length discrepancy, overgrowth, and associated risk factors after a pediatric tibial shaft fracture.

BACKGROUND: This study was performed to investigate leg length discrepancy (LLD), overgrowth, and associated risk factors after pediatric tibial shaft fractures. MATERIALS AND METHODS: This study included 103 patients younger than 14 years of age (mean age 7.1 years; 75 boys, 28 girls) with unilateral tibial shaft fracture and a minimum follow-up of 24 months. LLD was calculated as the difference between the lengths of the injured and uninjured limbs. Overgrowth was calculated by adding the fracture site shortening from the LLD. Risk factors were assessed in patients with LLD < 1 cm and ≥ 1 cm and overgrowth < 1 cm and ≥ 1 cm. RESULTS: Casting and titanium elastic nailing (TEN) were performed on 64 and 39 patients, respectively. The mean LLD and overgrowth were 5.6 and 6.4 mm, respectively. There were significant differences in sex (p = 0.018), age (p = 0.041), fibular involvement (p = 0.005), injury mechanism (p = 0.006), and treatment methods (p < 0.001) between patients with LLDs < 1 cm and ≥ 1 cm. There were significant differences in sex (p = 0.029), fibular involvement (p = 0.002), injury mechanism (p = 0.008), and treatment methods (p < 0.001) between patients with overgrowth < 1 cm and ≥ 1 cm. Sex and treatment methods were risk factors associated with LLD ≥ 1 cm and overgrowth ≥ 1 cm following pediatric tibial shaft fracture. The boys had a 7.4-fold higher risk of LLD ≥ 1 cm and 5.4-fold higher risk of overgrowth ≥ 1 cm than the girls. Patients who underwent TEN had a 4.3-fold higher risk of LLD ≥ 1 cm and 4.8-fold higher risk of overgrowth ≥ 1 cm than those treated by casting. CONCLUSIONS: Patients undergoing TEN showed greater LLD and overgrowth than those undergoing casting, with boys showing greater LLD and overgrowth than girls. Surgeons should consider the possibility of LLD and overgrowth after pediatric tibial shaft fractures, especially when performing TEN for boys. LEVEL OF EVIDENCE: Level III.

Outcomes After Double-Bundle Anterior Cruciate Ligament Reconstruction.

PURPOSE: To identify the risk factors predicting unsatisfactory postoperative clinical outcomes after double-bundle (DB) anterior cruciate ligament (ACL) reconstruction using multivariate logistic regression. METHODS: Inclusion criteria were consecutive DB ACL reconstructions from January 2006 to September 2012 with a minimum 3-year follow-up. Exclusion criteria included (1) a delay to surgery from initial injury of more than 4 years (210 weeks); (2) contralateral knee pathology; (3) the lack of postoperative 3-dimensional computed tomography; (4) single-bundle ACL reconstruction; (5) revision ACL reconstruction; (6) meniscus allograft transplantation after total or subtotal meniscectomy; (7) multiple ligament surgeries. According to the overall International Knee Documentation Committee (IKDC) rating at the last follow-up, we sorted all enrolled subjects into superior (IKDC grade A or B) and inferior outcome groups (IKDC grade C or D). Multivariate logistic regression was used to analyze risk factors, including age, gender, body mass index, time from injury to surgery, posterior tibial slope, notch width index, cartilage injury, meniscus injury, and femoral and tibial tunnel positions. RESULTS: In comparison between the superior outcome group (n = 240) and inferior outcome group (n = 50), anterior (adjusted odds ratio [OR]: 0.902, 95% confidence interval [CI]: 0.846-0.962) or distal (adjusted OR: 1.025, 95% CI: 1.006-1.060) femoral anteromedial tunnel position was a significant risk factor for the inferior outcomes. Partial meniscectomy of medial (adjusted OR: 49.002, 95% CI: 7.047-340.717) or lateral (adjusted OR: 14.974, 95% CI: 2.181-102.790) meniscus and delayed time from injury to surgery (adjusted OR: 1.062, 95% CI: 1.023-1.102) were also a significant predictor. CONCLUSION: Anterior or distal anteromedial femoral tunnel position, partial meniscectomy of medial or lateral meniscus, and prolonged surgical delay of more than 11.5 weeks from injury were significant risk factors for the inferior clinical outcomes after DB ACL reconstruction. LEVEL OF EVIDENCE: Level III, retrospective therapeutic case series.

Consistency and Reliability of Ankle Stress Radiography in Patients With Chronic Lateral Ankle Instability.

BACKGROUND: Ankle stress radiographs are important tools for evaluating chronic lateral ankle instability. The consistency of a patient's ankle condition as it affects the reliability of ankle stress radiographs has never been evaluated. PURPOSE: To investigate the consistency and reliability of ankle stress radiographs in patients with chronic lateral ankle instability without an ankle injury during the study period. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: Included were patients with chronic lateral ankle instability who underwent 2 repeated ankle stress radiographs between January 2014 and July 2019; those with an ankle injury during the study period were excluded. The tibiotalar tilt angle on varus stress radiographs and anterior translation of the talus on anterior drawer stress radiographs were measured at initial presentation and final follow-up examination. Interobserver reliability and consistency of ankle stress radiographs were analyzed using the intraclass correlation coefficient (ICC). RESULTS: A total of 45 patients (mean ± standard deviation age, 36.4 ± 13.4 years; 18 men and 27 women; follow-up duration, 9.1 ± 3.2 months) were included. The mean ± standard deviation tibiotalar tilt angle and anterior talar translation at initial presentation were 10.8° ± 5.2° and 6.9 ± 2.7 mm, respectively. The interobserver reliabilities of the tibiotalar tilt angle and anterior talar translation were excellent (ICC = 0.926 [95% CI, 0.874-0.959] and 0.911 [95% CI, 0.766-0.961], respectively). The consistency between the initial and final radiographs was good for tibiotalar tilt angle (ICC = 0.763 [95% CI, 0.607-0.862]) and poor for anterior talar translation (ICC = 0.456 [95% CI, 0.187-0.660]). CONCLUSION: Although the interobserver reliability of the radiographic measurements was excellent, the consistency of the ankle stress radiographs was not as acceptable. Surgeons need to be cautious when deciding whether to operate on a patient with chronic lateral ankle instability based on a single ankle stress radiograph.

Leg-length discrepancy and associated risk factors after paediatric femur shaft fracture: a multicentre study.

PURPOSE: This study was performed to investigate leg-length discrepancy (LLD) and associated risk factors after paediatric femur shaft fractures. METHODS: A total of 72 consecutive patients under 13 years old (mean age 6.7 years; 48 boys, 24 girls) with unilateral femur shaft fracture, and a minimum follow-up of 18 months, were included. The amount of LLD was calculated by subtracting the length of the uninjured from that of the injured limb. Risk factors for an LLD ≥ 1 cm and ≥ 2 cm were analyzed using multivariable logistic regression analysis. RESULTS: Hip spica casting, titanium elastic nailing and plating were performed on 22, 40 and ten patients, respectively. The mean LLD was 7.8 mm (sd 8.8) and 29 (40.3%) had a LLD of ≥ 1 cm, while nine (12.5%) had a LLD of ≥ 2 cm. There were significant differences in fracture stability (p = 0.005) and treatment methods (p = 0.011) between patients with LLD < 1 cm and ≥ 1 cm. There were significant differences in fracture site shortening (p < 0.001) and LLD (p < 0.001) between patients with length-stable and length-unstable fractures. Fracture stability was the only factor associated with LLD ≥ 1 cm (odds ratio of 4.0; p = 0.020) in the multivariable analysis. CONCLUSION: This study demonstrated that fracture stability was significantly associated with LLD after paediatric femur shaft fractures. Therefore, the surgeon should consider the possibility of LLD after length-stable femur shaft fracture in children. LEVEL OF EVIDENCE: Prognostic level III.

Growth arrest and its risk factors after physeal fracture of the distal tibia in children and adolescents.

BACKGROUND: . This study performed to investigate the incidence of growth arrest such as leg length discrepancy (LLD) and ankle joint angular deformity and its risk factors after physeal fracture of the distal tibia in children and adolescents. MATERIALS AND METHODS: . Consecutive 78 patients (mean age 11.4 ± 2.0 years; mean follow-up period 2.0 ± 1.2 years) treated for the distal tibia physeal fracture were included. All patients underwent preoperative ankle radiographs, three-dimensional computed tomography (CT) scans, and postoperative follow-up teleradiogram. Patients were divided into two groups according to the LLD and the difference of lateral distal tibial angle (LDTA) with the contralateral limb as follows: Group 1 (growth arrest), patients with LLD ≥ 1cm or difference of LDTA ≥ 5°; Group 2 (normal growth), patients with LLD < 1cm and difference of LDTA < 5°. RESULTS: . The overall incidence of growth arrest was 12.8% (10 of 78). The mean displacement measured using CT scan was 4.4 ± 3.2 mm (range, 0.8-14.9). Of the total 78 fractures, 65 were treated surgically and 13 fractures were treated conservatively. The initial fracture displacement was significantly different between the two groups (p<0.001). However, there were no statistically significant differences between the two groups with respect to other factors. Initial displacement was the only significant risk factor for growth arrest (p<0.003). The cutoff values of initial displacement between the two groups were 5.2mm. CONCLUSIONS: . This study showed that degree of initial displacement was the only significant risk factor for growth arrest after physeal fracture of the distal tibia in children and adolescents. Therefore, physicians should consider the possibility of growth arrest for patients with severely displaced physeal fractures of the distal tibia.